Shanghai – October 12, 2026 -- Shanghai Ark Biopharmaceutical (ArkBio) has received U.S. Food and Drug Administration clearance of its investigational new drug application for AK0406, allowing a phase II trial of the long-acting antiviral drug-Fc conjugate for influenza prevention in the general U.S. population.
CDC data shows 24,000 U.S. flu deaths despite vaccines
The U.S. Centers for Disease Control and Prevention reports that the 2025–2026 influenza season caused at least 32 million illnesses, 380,000 hospitalizations and 24,000 deaths in the United States. ArkBio says shifting circulating viruses and variable immune response limit vaccine protection, particularly among older adults and immunocompromised people.
AK0406 links multiple small-molecule antivirals to an antibody Fc domain
The drug is designed to combine direct antiviral activity with Fc-mediated immune clearance. In preclinical studies, it showed broad-spectrum, highly potent activity against influenza A and B strains. ArkBio has also optimized its pharmacokinetics and GMP manufacturing process.
Phase I dosing finished in Australia before China and U.S. clearances
An Australian Human Research Ethics Committee approved the phase I trial in February 2026. By July 2026, enrollment and dosing of healthy adults had been completed across all cohorts, and the study had entered follow-up. China's National Medical Products Administration cleared the IND for influenza prevention in August 2026.
U.S. phase II study will run during an influenza season
The multicenter, randomized, double-blind, placebo-controlled trial in adults will evaluate AK0406 for influenza prevention as its primary objective. It will also assess safety, tolerability, pharmacokinetics and immunogenicity, and the data will inform the global development strategy.
ArkBio plans to continue talks with the FDA and the Center for Drug Evaluation of China's NMPA to advance phase II development in both countries in parallel.